A hormone normally found in the blood and urine during pregnancy. It may also be produced by some tumor cells. An increased level of beta-hCG may be a sign of cancer of the testis, uterus, ovary, liver, stomach, pancreas, or lung. Beta-hCG may also be produced in response to certain conditions that are not cancer. Beta-hCG is being studied in the treatment of Kaposi sarcoma. Also called beta-human chorionic gonadotropin.